A study on the effect of reaction temperature on the synthesis of magnesium hydroxide nanoparticles: Comparative evaluation of microstructure parameters and optical properties

[Display omitted] •Two different sizes of magnesium hydroxide nanoparticles were synthesized by varying the reaction temperature.•The Size and microstrain of the synthesized NPs were estimated and compared using the Debye-Scherrer (DS), Williamson-Hall (WH), size-strain plot (SSP), and Halder-Wagner (HW) theoretical methods.•Blue shift in the absorption spectrum indicates size quantization effects and validates the XRD results and Tauc’s plot estimation.•Fourier-transform infrared spectroscopy (FTIR) and SEM- Energy dispersive X-ray spectroscopy (EDS) analysis was performed to confirm the formation of magnesium hydroxide NPs. In the present work, magnesium hydroxide nanoparticles were synthesized using the coprecipitation method with the variation of the reaction temperature. The effects of variation of the reaction temperature on the morphological and optical properties were discussed in this paper. The synthesized NPs were characterized using X-ray diffraction, Scanning electron microscope with energy dispersive X-ray spectroscopy, Fourier transform infrared spectrometer, UV–visible absorption, and fluorescence techniques. The crystallite size of the NPs was estimated using various theoretical methods such as Debye-Scherrer (DS), Williamson-Hall (WH), size-strain plot (SSP), and Halder-Wagner (HW) methods and noticed that all the methods have yielded nearly same crystallite size, which ranges between 10 -12 nm for MH A and 7–8 nm for MH B NPs, respectively. The synthesized NPs have shown the shape of flakes and agglomerated particle distribution. These NPs have also shown broad absorption and narrower emission band in the visible region, which suggests that these have potential applications in the field of biological markers, sensors and light-harvesting devices.